upstart-event-bridge

upstart-event-bridge EVENT [KEY1=VALUE1 KEY2=VALUE2 ...]

EVENT
    The name of the event to be emitted. This is a string that will be used to identify the event within the Upstart system.

KEY=VALUE
    Optional key-value pairs to be passed along with the event. These key-value pairs can be used to provide additional context or data to the Upstart jobs that are triggered by the event.

The `upstart-event-bridge` command is a utility used to trigger Upstart events from the command line. It acts as a bridge between shell commands or scripts and the Upstart event system. This allows for custom events to be generated, which can then be used to start, stop, or otherwise manage services configured with Upstart.

The command sends a formatted event to the Upstart event system. Jobs configured to react to that event will then be triggered according to their configuration. It can be used to signal state changes in the system, or to initiate tasks based on external factors. It is a fundamental component for managing services and defining dependencies when using the Upstart init system. It simplifies the process of interacting with the Upstart event system directly.

Upstart is largely deprecated in favor of systemd on most modern Linux distributions. This command may not be available or functional on newer systems. Using systemd's `systemctl` command or dbus for event triggering is recommended on systemd based distributions.

Example 1: Trigger a simple event:
upstart-event-bridge my_event

Example 2: Trigger an event with key-value pairs:
upstart-event-bridge application_started version=1.2.3 status=ok

Example 3: Trigger an event from a script:
Within a shell script, you might trigger an event based on some condition, for example:
if [ "$exit_code" -eq 0 ]; then upstart-event-bridge task_completed status=success; else upstart-event-bridge task_completed status=failed; fi

The `upstart-event-bridge` command was developed as part of the Upstart init system. Upstart aimed to improve upon traditional System V init systems by introducing an event-driven approach to service management. `upstart-event-bridge` provided a straightforward way for users and scripts to integrate with this event system, enabling dynamic and flexible service orchestration. It has since been superseded by systemd in many Linux distributions.

initctl(8), start(1), stop(1), restart(1)